Flange Center Friction Increase

[Chris Gregg]

I have a Samick grand action on my bench right now.  The problem I thought 
was sticking jacks, but on further investigation, the problem was the 
flange on the top of the repetition post. The repetition was not returning 
and therefore the jack was sticking on the knuckle.  I punched out the pin 
and noticed a residue on it, so then I punched out the bushing cloth to see 
what the problem really was.  The cloth was hard.  Too much glue on it, 
making the graphite stick to the pin.  I re-bushed and re-pinned the 
offender, however, I do not see doing this to all the bad ones.   I have 
re-pinned thousands of Young Chang action centres over the years.  I was 
led to believe that there was a sizing problem with the action centre cloth 
at one time.  Rep[inning I can handle, re-bushing is a pain in the you know 
what.

Chris Gregg RPT

  At 07:50 PM 7/20/2003 +1000, you wrote:
>No matter how 'gently' i try, i have never been able to put a cut centre 
>pin back in a bushing without knocking out the cloth! I would not 
>recommend trying this to anyone (unless they really want practise at 
>re-bushing flanges!).
>
>Scott Jackson
>Australia
>
>----- Original Message -----
>From: "Paul Chick (Earthlink)" <tune4@earthlink.net>
>To: "Pianotech" <pianotech@ptg.org>
>Sent: Saturday, July 19, 2003 10:07 AM
>Subject: RE: Flange Center Friction Increase
>
>
>| Terry
>| Isaac Sadisgursky talked about this in his class on center pins at the
>| Convention.  He demonstrated how a center pin can be too tight in the
>| bushing cloth and loose through the wood, just the opposite of what it
>| should be.  This problem can be spotted as you describe--fewer swings as you
>| go along.  Here's his test: carefully remove the center pin from an
>| offending flange. Gently place it back in the bushed flange and check the
>| friction just by pushing the pin with your fingernail. Now place the same
>| pin in the wood and push it with your fingernail.  Chances are you can push
>| it right through the wood.  The problem is caused by using the assembly wire
>| used in the flange to size the bushing cloth during manufacturing.  When the
>| flange is installed, the worker slides the wire back to clear the other
>| member then slides it through and cuts it to length, fitting done.  Isaac
>| says to watch for centers that are clipped on both sides of the flange.
>| This will tell you a wire had been used.  He then went on to demonstrate how
>| to repin a set of flanges in about 45 minutes.
>| Paul C
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